Ancestral Notch-mediated segmentation revealed in the cockroach Periplaneta americana.
Through division into segments, animal bodies can reach higher degrees of complexity and functionality during development and evolution. The segmentation mechanisms of insects and vertebrates have been seen as fundamentally different at the anatomical and molecular levels, and consequently, independently evolved. However, this conclusion was mostly based on observations of derived insects such as Drosophila. We have cloned the Delta, Notch, and hairy genes in the cockroach Periplaneta americana, a basal insect with short germ-band development, and carried out functional assays of Notch activity during its segmentation. Our results show that, in more basal insects, segmentation involves a similar developmental mechanism to that in vertebrates, including induction of segment formation by cyclic segmental stripes of hairy and Delta expression. This result indicates that Notch-mediated segmentation is the ancestral segmentation mechanism of insects, and together with previous results in the literature [Stollewerk A, Schoppmeier M, Damen WGM (2003) Nature 423:863-865], of arthropods as well. The similarity with vertebrate segmentation might suggest that Notch-mediated segmentation is an ancient developmental mechanism inherited from a common ancestor of insects and vertebrates.
Pueyo
J I
JI
School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, United Kingdom.
Lanfear
R
R
Couso
J P
JP
D000818:Animals; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics; D005075:Biological Evolution; D019521:Body Patterning / Q000235:genetics*; D004625:Embryo, Nonmammalian; D018507:Gene Expression Regulation, Developmental; D019476:Insect Proteins / Q000235:genetics; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D010526:Periplaneta / Q000235:genetics* / Q000254:growth & development; D051880:Receptors, Notch / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics
D051792:Basic Helix-Loop-Helix Proteins; D019476:Insect Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D051880:Receptors, Notch; D012097:Repressor Proteins; C064045:delta protein; C061841:hairy protein, insect